The utility of metasurfaces has been praised many times; some even say they have the potential to replace traditional optics [1]}, [2]}, [3]}. However, their integration in conventional lens design remains a little-explored avenue. Considering metasurfaces in a complete optical system is inconceivable if common time-consuming numerical methods are used. The macroscopic scale of elements and the large number of iterations required to design a suitable system [4]} would require too much computing power. Therefore, a method to efficiently represent metasurfaces in a ray-tracing process is needed. Such a method could originate from modelling the optical properties of meta-atoms.
